package com.yujian.weixin;
import org.weixin4j.util.TokenUtil;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletInputStream;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.weixin4j.spi.IMessageHandler;
import org.weixin4j.Configuration;
import org.weixin4j.spi.HandlerFactory;
public class CustomWeixinUrlFilter implements Filter {

    @Override
    public void init(FilterConfig config) throws ServletException {
        if (Configuration.isDebug()) {
            System.out.println("WeixinUrlFilter启动成功!");
        }
    }

    @Override
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) req;
        HttpServletResponse response = (HttpServletResponse) res;
        //微信服务器将发送GET请求到填写的URL上,这里需要判定是否为GET请求

        boolean isGet = request.getMethod().toLowerCase().equals("get");
        if (Configuration.isDebug()) {
            System.out.println("获得微信请求:" + request.getMethod() + " 方式");
            System.out.println("微信请求URL:" + request.getServletPath());
        }
        //消息来源可靠性验证

        String signature = request.getParameter("signature");// 微信加密签名

        String timestamp = request.getParameter("timestamp");// 时间戳

        String nonce = request.getParameter("nonce");       // 随机数

        //Token为weixin4j.properties中配置的Token

        String token = TokenUtil.get();
        if (isGet) {
            //1.验证消息真实性

            //http://mp.weixin.qq.com/wiki/index.php?title=验证消息真实性

            //URL为http://www.weixin4j.org/api/公众号

            //成为开发者验证

            String echostr = request.getParameter("echostr");   //

            //确认此次GET请求来自微信服务器，原样返回echostr参数内容，则接入生效，成为开发者成功，否则接入失败

            if (TokenUtil.checkSignature(token, signature, timestamp, nonce)) {
                response.getWriter().write(echostr);
            }
        } else {
            //确认此次GET请求来自微信服务器，原样返回echostr参数内容，则接入生效，成为开发者成功，否则接入失败

            if (!TokenUtil.checkSignature(token, signature, timestamp, nonce)) {
                //消息不可靠，直接返回

                response.getWriter().write("");
                return;
            }
            //用户每次向公众号发送消息、或者产生自定义菜单点击事件时，响应URL将得到推送

            doPost(request, response);
        }
    }

    //当普通微信用户向公众账号发消息时，微信服务器将POST消息的XML数据包到开发者填写的URL上

    //用户在关注与取消关注公众号时，微信会把这个事件推送到开发者填写的URL

    //用户每次发送语音给公众号时，微信会在推送的语音消息XML数据包中，增加一个Recongnition字段

    private void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException {
        try {
            response.setCharacterEncoding("UTF-8");
            response.setContentType("text/xml");
            //获取POST流

            ServletInputStream in = request.getInputStream();
            if (Configuration.isDebug()) {
                System.out.println("接收到微信输入流,准备处理...");
            }
  //          IMessageHandler messageHandler = HandlerFactory.getMessageHandler();
  //这里改成自定义的消息处理类
            IMessageHandler messageHandler = new CustomMessageHandler();
            //处理输入消息，返回结果

            String xml = messageHandler.invoke(in);
            //返回结果

            response.getWriter().write(xml);
        } catch (Exception ex) {
            ex.printStackTrace();
            response.getWriter().write("");
        }
    }

    @Override
    public void destroy() {
    }
}
